The EPA is proposing to retain the current national air quality standards for carbon monoxide (CO), while taking additional steps to monitor and gather data.
Scientific data shows that current standards protect people from health problems associated with breathing CO in the outdoor air.
CO can cause harmful health problems and even death by reducing oxygen deliver to the body's organs, such as the heart, brain, and tissues.
Current health standards are 9 parts per million (ppm) measured over 8 hours, and 35 ppm measured over 1 hour. Proposed changes would bring a more focused approach to monitoring CO, with monitors placed near highly trafficked roads in urban areas with populations of 1 million or more. Data from these sites would be utilized in future reviews of air quality standards.
New monitoring equipment is not expected to be needed, existing CO monitors will be relocated to near-road stations already required by standards issued in January 2010. Approximately 77 CO monitors in 53 urban areas are called for in the proposed changes.
CO monitors called for by the national air quality standards are scheduled to be operational by January 1, 2013.